The Latin term Imperium Romanum (Roman Empire), probably the best-known Latin expression where the word imperium denotes a territory, indicates the part of the world under Roman rule. Roman expansion began in the days of the Republic, but reached its zenith under Emperor Trajan. At this territorial peak, the Roman Empire controlled approximately 5,900,000 km² (2,300,000 sq mi) of land surface. Because of the Empire's vast extent and long endurance, Roman influence upon the language, religion, architecture, philosophy, law, and government of nations around the world lasts to this day.

In the late 3rd century AD, Diocletian established the practice of dividing authority between two emperors, one in the western part of the empire and one in the east, in order to better administer the vast territory. For the next century this practice continued, with occasional periods in which one emperor assumed complete control. However, after the death of Theodosius the Great in 395, no single emperor would ever again hold genuine supremacy over a united Roman Empire . The Western Roman Empire collapsed in 476 as Romulus Augustus was forced to abdicate by Odoacer . The Eastern Roman or Byzantine Empire endured until 1453 with the capture of Constantinople by the Ottoman Turks led by Mehmed II . Therefore, it is difficult to give an exact date when the Roman Empire ceased to exist, but this article will focus on the empire from 27 BC to the permanent division in AD 395. For more information, see History of the Roman Empire.

Government

Emperor

The powers of an emperor, (his imperium) existed, in theory at least, by virtue of his "tribunician powers" (potestas tribunicia) and his "proconsular powers" (imperium proconsulare). In theory, the tribunician powers (which were similar to those of the Plebeian Tribunes under the old republic) made the emperor's person and office sacrosanct, and gave the emperor authority over Rome's civil government, including the power to preside over and to control the Senate. The proconsular powers (similar to those of military governors, or Proconsuls, under the old republic) gave him authority over the Roman army. He was also given powers that, under the republic, had been reserved for the Roman Senate and the Roman assemblies, including the right to declare war, to ratify treaties, and to negotiate with foreign leaders. The emperor also had the authority to carry out a range of duties that had been performed by the Roman Censors, including the power to control senate membership. In addition, the emperor controlled the religious institutions, since, as emperor, he was always Pontifex Maximus and a member of each of the four major priesthoods. While these distinctions were clearly defined during the early empire, eventually they were lost, and the emperor's powers became less constitutional and more monarchical.

Realistically, the main support of an emperor's power and authority was the military. Being paid by the imperial treasury, the legionaries also swore an annual military oath of loyalty towards him, called the Sacramentum. The death of an emperor led to a crucial period of uncertainty and crisis. In theory the senate was entitled to choose the new emperor, but most emperors choose their own successors, usually a close family member. The new emperor had to seek a swift acknowledgement of his new status and authority in order to stabilize the political landscape. No emperor could hope to survive, much less to reign, without the allegiance and loyalty of the Praetorian Guard and of the legions. To secure their loyalty, several emperors paid the Donativum, a monetary reward.

Senate

While the Roman assemblies continued to meet after the founding of the empire, their powers were all transferred to the Roman Senate, and so senatorial decrees (senatus consulta) acquired the full force of law.

In theory, the emperor and the senate were two co-equal branches of government, but the actual authority of the senate was negligible and it was largely a vehicle through which the emperor disguised his autocratic powers under a cloak of republicanism. Still prestigious and respected, the Senate was largely a glorified rubber stamp institution which had been stripped of most of its powers, and was largely at the emperor's mercy.

Many emperors showed a certain degree of respect towards this ancient institution, while others were notorious for ridiculing it. During senate meetings, the emperor sat between the two Roman Consuls, and usually acted as the presiding officer. Higher ranking senators spoke before lower ranking senators, although the emperor could speak at any time. By the third century, the senate had been reduced to a glorified municipal body.

Senators and Equestrians

No emperor could rule the empire without the Senatorial Order and the Equestrian Order. Most of the more important posts and offices of the government were reserved for the members of these two aristocratic orders. It was from among their ranks that the provincial governors, legion commanders, and similar officials were chosen.

These two classes were hereditary and mostly closed to outsiders. Very successful and favoured individuals could enter, but this was a rare occurrence. The careers of the young aristocrats was influenced by their family connections and the favour of patrons. As important as ability, knowledge, skill, or competence; patronage was considered vital for a successful career and the highest posts and offices required the emperor's favour and trust.

Senatorial Order

The son of a senator was expected to follow the Cursus honorum, a career ladder, and the more prestigious positions were restricted to senators only. A senator also had to be wealthy; one of the basic requirements was the wealth of 12,000 gold Aurei , a figure which would later be raised with the passing of centuries.

Equestrian Order

Below the Senatorial Order was the Equestrian Order. The requirements and posts reserved for this class, while perhaps not so prestigious, were still very important. Some of the more vital posts, like the governorship of Aegyptus, were even forbidden to the members of the Senatorial Order and available only to equestrians.

Military

Legions

During and after the civil war, Octavian reduced the huge number of the legions (over 60 ) to a much more manageable and affordable size (28 ). Several legions, particularly those with doubtful loyalties, were simply disbanded. Other legions were amalgamated, a fact suggested by the title Gemina (Twin ). In AD 9 Germanic tribes wiped out three full legions in the Battle of the Teutoburg Forest. This disastrous event reduced the number of the legions to 25. The total of the legions would later be increased again and for the next 300 years always be a little above or below 30 . Augustus also created the Praetorian Guard: nine cohorts ostensibly to maintain the public peace which were garrisoned in Italy. Better paid than the legionaries, the Praetorians also served less time; instead of serving the standard 25 years of the legionaries, they retired after 16 years of service .

Auxillia

While the Auxillia (Latin: auxilia = supports) are not as famous as the legionaries, they were of major importance. Unlike the legionaries, the auxilia were recruited from among the non-citizens. Organized in smaller units of roughly cohort strength, they were paid less than the legionaries, and after 25 years of service were rewarded with Roman citizenship, also extended to their sons. According to Tacitus there were roughly as many auxiliaries as there were legionaries. Since at this time there were 25 legions of around 5,000 men each, the auxilia thus amounted to around 125,000 men, implying approximately 250 auxiliary regiments .

Navy

The Roman Navy (Latin: Classis, lit. "fleet") not only aided in the supply and transport of the legions, but also helped in the protection of the frontiers in the rivers Rhine and Danube. Another of its duties was the protection of the very important maritime trade routes against the threat of pirates. Therefore it patrolled the whole of the Mediterranean Sea, parts of the North Atlantic (coasts of Hispania, Gaul, and Britannia), and had also a naval presence in the Black Sea. Nevertheless the army was considered the senior and more prestigious branch .

Provinces

In the old days of the Republic the governorships of the provinces were traditionally awarded to members of the Senatorial Order. Augustus' reforms changed this policy.

Imperial provinces

Augustus created the Imperial provinces. Most, but not all, of the Imperial provinces were relatively recent conquests and located at the borders. Thereby the overwhelming majority of legions, which were stationed at the frontiers, were under direct Imperial control. Very important was the Imperial province of Aegyptus (modern Egypt), the major breadbasket of the empire. Its grain supply was vital to feed the masses in Rome. It was considered the personal fiefdom of the emperor, and Senators were forbidden to even visit this province. The governor of Aegyptus and the commanders of any legion stationed there were not from the Senatorial Order, but were chosen by the emperor from among the members of the lower Equestrian Order.

Senatorial provinces

The old traditional policy continued largely unchanged in the Senatorial provinces. Due to their location, away from the borders, and to the fact that they were under longer Roman sovereignty and control, these provinces were largely peaceful and stable. Only a single legion was based in a Senatorial province: Legio III Augusta, stationed in the Senatorial province of Africa (modern northern Algeria).

The status of a province was subject to change; it could change from Senatorial towards Imperial, or vice-versa. This happened several times during Augustus' reign. Another trend was to create new provinces, mostly by dividing older ones, or by expanding the empire.

Religion

As the empire expanded, and came to include people from a variety of cultures, the worship of an ever increasing number of deities was tolerated and accepted. The imperial government, and the Romans in general, tended to be very tolerant towards most religions and cults. However a select few religions were not widely accepted, and on occasion even persecuted.

Imperial cult

In an effort to enhance loyalty, the inhabitants of the empire were called to participate in the Imperial cult and revere the emperors and certain members of the imperial family as gods. The importance of the Imperial cult slowly grew, reaching its peak during the Crisis of the Third Century. Especially in the eastern half of the empire imperial cults grew very popular, and the cult complex became one of the focal points of life in the Roman cities. As such it was one of the major agents of romanization. The central elements of the cult complex were next to a temple; a theatre or amphitheatre for gladiator displays and other games and a public bath complex. Sometimes the imperial cult was added to the cults of an existing temple or celebrated in a special hall in the bath complex.

The seriousness of this belief is unclear. Some Romans ridiculed the notion that a Roman emperor was to be considered a living god, or would even make fun of the deification of an emperor after his death. Seneca the Younger parodied the notion of apotheosis in his only known satire The Pumpkinification of Claudius, in which the clumsy and ill-spoken Claudius is not transformed into a god, but into a pumpkin. In fact, bitter sarcasm was already effected at Claudius' funeral in 54 .

Absorption of foreign cults

Persecuted religions

Druids

Druids were seen as essentially non-Roman: a prescript of Augustus forbade Roman citizens to practice "druidical" rites. Pliny reports that under Tiberius the druids were suppressed—along with diviners and physicians—by a decree of the Senate, and Claudius forbade their rites completely in AD 54 .

Judaism

While Judaism was largely tolerated, it was on occasion subject to (mostly) local persecution.

Tiberius forbade Judaism in Rome, and Claudius expelled them from the city. However the passage of Suetonius is ambiguous: "Because the Jews at Rome caused continuous disturbances at the instigation of Chrestus he [Claudius] expelled them from the city" . Chrestus has been identified as another form of Christus; the disturbances may have been related to the arrival of the first Christians, and that the Roman authorities, failing to distinguish between the Jews and the early Christians, simply decided to expel them all.

Christianity

As Christianity began to spread throughout the empire it was initially largely left in peace.

Suetonius mentions passingly that: "[during Nero's reign] Punishments were also inflicted on the Christians, a sect professing a new and mischievous religious belief" but he doesn't explain for what they were punished.

Tacitus reports that after the Great Fire of Rome in AD 64 some in the population held Nero responsible and that to diffuse blame, he targeted and blamed the Christians .

Languages

The major languages of the Roman Empire were Latin and Greek. Greek was the long established lingua franca in the Mediterranean and very important in the eastern provinces, while the influence of Latin was stronger in the western provinces and there it slowly gained in importance. The imperial bureaucracy worked in both languages, and two official secretaries dealt with the correspondence, in Greek for the eastern provinces, and in Latin for the western provinces.

By the time of the imperial period Latin had evolved into two languages: the 'high' written Classical Latin and the 'low' spoken Vulgar Latin. While Classical Latin remained relatively stable, Vulgar Latin was, as with any spoken language, continually fluid and slowly evolving. Greek had also evolved into Attic and Koine Greek. Greek and Classical Latin were considered the languages of literature, scholarship, and education. One of the passages of The Twelve Caesars even tells us that, as a barbarian addressed emperor Claudius in both Greek and in Latin, the reply of the emperor began with: "Since you come armed with both our languages..." . Claudius is also the last known person to study and to write Etruscan which seems to have died out in the 1st century AD.

Nearly all educated persons in the East could speak Greek, just as all educated persons in the West spoke Latin and Greek, but a great proportion of ordinary people spoke neither. In the enormous and multi-ethnic empire several other languages were spoken, some even gaining local official status during some periods. Aramaic and Syriac were spoken in certain eastern provinces and, in addition to Greek, became accepted literary languages used by the local elite. Also important were Coptic in Egypt, and Armenian in Armenia, while Punic seems to have entered a period of slow decline. Hard knowledge about the various Celtic dialects and languages is sadly lacking.

Most Roman towns and cities had a forum and temples, as did the city of Rome itself. Aqueducts were built to bring water to urban centres and wine and oil were imported from abroad. Landlords generally resided in cities and their estates were left in the care of farm managers. To stimulate a higher labour productivity, many landlords freed a large numbers of slaves. By the time of Augustus, cultured Greek household slaves taught the Roman young (sometimes even the girls). Greek sculptures adorned Hellenistic landscape gardening on the Palatine or in the villas.

Many aspects of Roman culture were taken from the Greeks. In architecture and sculpture, the difference between Greek models and Roman paintings are apparent. The chief Roman contributions to architecture were the arch and the dome.

The centre of the early social structure was the family, which was not only marked by blood relations but also by the legally constructed relation of patria potestas. The Pater familias was the absolute head of the family; he was the master over his wife, his children, the wives of his sons, the nephews, the slaves and the freedmen, disposing of them and of their goods at will, even putting them to death. Roman law recognized only patrician families as legal entities.

Slavery and slaves were part of the social order; there were slave markets where they could be bought and sold. Many slaves were freed by the masters for services rendered; some slaves could save money to buy their freedom. Generally mutilation and murder of slaves was prohibited by legislation. It is estimated that over 25% of the Roman population was enslaved.

Clothing, dining, and the arts

The cloth and the dress distinguished one class of people from the other class. The tunic worn by plebeians (common people) like shepherds and slaves was made from coarse and dark material, whereas the tunic worn by patricians was of linen or white wool. A magistrate would wear the tunic augusticlavi; senators wore a tunic with broad stripes, called tunica laticlavi. Military tunics were shorter than the ones worn by civilians. Boys, up until the festival of Liberalia, wore the toga praetexta, which was a toga with a crimson or purple border. The toga virilis, (or toga pura) was worn by men over the age of 16 to signify their citizenship in Rome. The toga picta was worn by triumphant generals and had embroidery of their skill on the battlefield. The toga pulla was worn when in mourning. Even footwear indicated a person’s social status. Patricians wore red and orange sandals, senators had brown footwear, consuls had white shoes, and soldiers wore heavy boots. Men typically wore a toga, and women a stola. The woman's stola looked different than a toga, and was usually brightly coloured. The Romans also invented socks for those soldiers required to fight on the northern frontiers, sometimes worn in sandals.

Romans had simple food habits. Staple food was simple, generally consumed at around 11 o’clock, and consisted of bread, salad, cheese, fruits, nuts, and cold meat left over from the dinner the night before. The Roman poet, Horace mentions another Roman favourite, the olive, in reference to his own diet, which he describes as very simple: "As for me, olives, endives, and smooth mallows provide sustenance. The family ate together, sitting on stools around a table. Fingers were used to eat solid foods and spoons were used for soups. Wine was considered a staple drink, consumed at all meals and occasions by all classes and was quite cheap. Many types of drinks involving grapes and honey were consumed as well. Drinking on an empty stomach was regarded as boorish and a sure sign for alcoholism, whose debilitating physical and psychological effects were known to the Romans. An accurate accusation of being an alcoholic was an effective way to discredit political rivals.

Roman literature was from its very inception influenced heavily by Greek authors. Some of the earliest works we possess are of historical epics telling the early military history of Rome. As the empire expanded, authors began to produce poetry, comedy, history, and tragedy. Virgil represents the pinnacle of Roman epic poetry. His Aeneid tells the story of flight of Aeneas from Troy and his settlement of the city that would become Rome. Lucretius, in his On the Nature of Things, attempted to explicate science in an epic poem. The genre of satire was common in Rome, and satires were written by, among others, Juvenal and Persius. Many Roman homes were decorated with landscapes by Greek artists. Portrait sculpture during the period utilized youthful and classical proportions, evolving later into a mixture of realism and idealism. Advancements were also made in relief sculptures, often depicting Roman victories.

Music was a major part of everyday life. The word itself derives from Greekμουσική (mousike), "(art) of the Muses". Many private and public events were accompanied by music, ranging from nightly dining to military parades and manoeuvres. In a discussion of any ancient music, however, non-specialists and even many musicians have to be reminded that much of what makes our modern music familiar to us is the result of developments only within the last 1,000 years; thus, our ideas of melody, scales, harmony, and even the instruments we use would not be familiar to Romans who made and listened to music many centuries earlier.

Over time, Roman architecture was modified as their urban requirements changed, and the civil engineering and buildingconstructiontechnology became developed and refined. The Roman concrete has remained a riddle, and even after more than 2,000 years some Roman structures still stand magnificently. The architectural style of the capital city was emulated by other urban centres under Roman control and influence.

Education

Following various military conquests in the Greek East, Romans adapted a number of Greek educational precepts to their own fledgling system. Home was often the learning centre, where children were taught Roman law, customs, and physical training to prepare the boys to grow as Roman citizens and for eventual recruitment into the army. Conforming to discipline was a point of great emphasis. Girls generally received instruction from their mothers in the art of spinning, weaving ,and sewing.

Education began at the age of around six, and in the next six to seven years, boys and girls were expected to learn the basics of reading, writing and counting. By the age of twelve, they would be learning Latin, Greek, grammar and literature, followed by training for public speaking. Oratory was an art to be practised and learnt, and good orators commanded respect. To become an effective orator was one of the objectives of education and learning. In some cases, services of gifted slaves were utilized for imparting education.

Economy

The imperial government was, as all governments, interested in the issue and control of the currency in circulation. To mint coins was a political act: the image of the ruling emperor appeared on most issues, and coins were a means of showing his image throughout the empire. Also featured were predecessors, empresses, other family members, and heirs apparent. By issuing coins with the image of an heir his legitimacy and future succession was proclaimed and reinforced. Political messages and imperial propaganda such as proclamations of victory and acknowledgements of loyalty also appeared in certain issues.

Legally only the emperor and the Senate had the authority to mint coins inside the empire . However the authority of the Senate was mainly in name only. In general, the imperial government issued gold and silver coins while the Senate issued bronze coins marked by the legend "SC", short for Senatus Consulto "by decree of the Senate". However, bronze coinage could be struck without this legend. Some Greek cities were allowed to mint bronze and certain silver coins, which today are known as Greek Imperials (also Roman Colonials or Roman Provincials). The imperial mints were under the control of a chief financial minister, and the provincial mints were under the control of the imperial provincial procurators. The Senatorial mints were governed by officials of the Senatorial treasury.

The Emperors

Augustus (27 BC–AD 14)

The Battle of Actium resulted in the defeat and subsequent suicides of Mark Antony and Cleopatra. Octavian, now sole ruler of Rome, began a full-scale reformation of military, fiscal and political matters. The powers that he secured for himself were identical in form, if not in name, to those that his predecessor Julius Caesar had secured years earlier as Roman Dictator. In 36 BC, he was given the power of a Plebeian Tribune, which gave him veto power over the senate, the ability to control the principle legislative assembly (the Plebeian Council), and made his person and office sacrosanct. Up until 32 BC, his status as a Triumvir gave him the powers of an autocrat, but when he deposed Mark Antony that year, he resigned from the Triumvirate, and was then given powers identical to those that he had given up. In 29 BC, Octavian was given the authority of a Roman Censor, and thus the power to appoint new senators.

The senate granted Octavian a unique grade of Proconsularimperium, which gave him authority over all Proconsuls (military governors). The unruly provinces at the borders, where the vast majority of the legions were stationed, were under the control of Augustus. These provinces were classified as imperial provinces. The peaceful senatorial provinces were under the control of the Senate. The Roman legions, which had reached an unprecedented number (around 50) because of the civil wars, were reduced to 28. Augustus also created nine special cohorts, ostensibly to maintain the peace in Italy, keeping at least three of them stationed at Rome. These cohorts became known as the Praetorian Guard. In 27 BC, Octavian transferred control of the state back to the Senate and the People of Rome. The Senate refused the offer, which, in effect, functioned as a popular ratification of his position within the state. Octavian was also granted the title of "Augustus" by the senate, and took the title of Princeps, or "first citizen".

As the adopted heir of Caesar, Augustus preferred to be called by this name. Caesar was a component of his family name. Julio-Claudian rule lasted for almost a century (from Julius Caesar in the mid-1st century BC to the emperor Nero in the mid-1st century AD). By the time of the Flavian Dynasty, and the reign of Vespasian, and that of his two sons, Titus and Domitian, the term Caesar had evolved, almost de facto, from a family name into a formal title.

Augustus' final goal was to figure out a method to ensure an orderly succession. In 6 BC Augustus granted tribunician powers to his stepson Tiberius, and before long Augustus realized that he had no choice but to recognize Tiberius as his heir. In 13 AD, the point was settled beyond question. A law was passed which linked Augustus' powers over the provinces to those of Tiberius, so that now Tiberius' legal powers were equivalent to, and independent from, those of Augustus. Within a year, Augustus was dead.

Tiberius to Alexander Severus (14–235)

Augustus was succeeded by his stepson Tiberius, the son of his wife Livia from her first marriage. Augustus was a scion of the gensJulia (the Julian family), one of the most ancient patrician clans of Rome, while Tiberius was a scion of the gensClaudia, only slightly less ancient than the Julians. Their three immediate successors were all descended both from the gens Claudia, through Tiberius's brother Nero Claudius Drusus, and from gens Julia, either through Julia the Elder, Augustus's daughter from his first marriage (Caligula and Nero), or through Augustus's sister Octavia Minor (Claudius). Historians thus refer to their dynasty as "Julio-Claudian Dynasty".

The early years of Tiberius's reign were peaceful and relatively benign. However, Tiberius's reign soon became characterised by paranoia and slander. He began a series of treason trials and executions, which continued until his death in 37. The logical successor to the hated Tiberius was his grandnephew, Gaius (better known as "Caligula" or "little boots"). Caligula started out well, but quickly became insane. In 41 Caligula was assassinated, and for two days following his assassination, the senate debated the merits of restoring the republic. Due to the demands of the army, however, Claudius was ultimately declared emperor. Claudius was neither paranoid like his uncle Tiberius, nor insane like his nephew Caligula, and was therefore able to administer the empire with reasonable ability. In his own family life he was less successful, as he married his niece, who may very well have poisoned him in 54. Nero, who succeeded Claudius, focused much of his attention on diplomacy, trade, and increasing the cultural capital of the empire. Nero, though, is remembered as a tyrant, and committed suicide in 68.

The forced suicide of Nero was followed by a brief period of civil war, known as the "Year of the Four Emperors". Augustus had established a standing army, where individual soldiers served under the same military governors over an extended period of time. The consequence was that the soldiers in the provinces developed a degree of loyalty to their commanders, which they did not have for the emperor. Thus the empire was, in a sense, a union of inchoate principalities, which could have disintegrated at any time. Between June 68 and December 69, Rome witnessed the successive rise and fall of Galba, Otho and Vitellius until the final accession of Vespasian, first ruler of the Flavian dynasty. These events showed that any successful general could legitimately claim a right to the throne.

Vespasian, though a successful emperor, continued the weakening of the Senate which had been going on since the reign of Tiberius. Through this sound fiscal policy, he was able to build up a surplus in the treasury, and began construction on the Colosseum. Titus, Vespasian's successor, quickly proved his merit, although his short reign was marked by disaster, including the eruption of Mount Vesuvius in Pompeii. He held the opening ceremonies in the still unfinished Colesseum, but died in 81. He was succeeded by his brother, Domitian, who had exceedingly poor relations with the senate. Domitian, ultimately, was a tyrant with the character which always makes tyranny repulsive, and this derived in part from the fact that he had no son, and thus was constantly in danger of being overthrown. In September of 96, he was murdered.

The next century came to be known as the period of the "Five Good Emperors", in which the successions were peaceful and the Empire was prosperous. Each emperor of this period was adopted by his predecessor. The last 2 of the "Five Good Emperors" and Commodus are also called Antonines. After his accession, Nerva, who succeeded Domitian, set a new tone: he restored much confiscated property and involved the Roman Senate in his rule. In 112, Trajan marched on Armenia and annexed it to the Roman Empire. Then he turned south into Parthia, taking several cities before declaring Mesopotamia a new province of the empire, and lamenting that he was too old to follow in the steps of Alexander the Great. During his rule, the Roman Empire was to its largest extent, and would never again advance so far to the east. Hadrian's reign was marked by a general lack of major military conflicts, but he had to defend the vast territories that Trajan had acquired. Antoninus Pius's reign was comparatively peaceful. During the reign of Marcus Aurelius, Germanic tribes launched many raids along the northern border. The period of the "Five Good Emperors" was brought to an end by the reign of Commodus. Commodus was the son of Marcus Aurelius, breaking the scheme of adoptive successors that had turned out so well. Commodus became paranoid and slipped into insanity before being murdered in 192.

The Severan Dynasty, which lasted from 193 until 235, included several increasingly troubled reigns. A generally successful ruler, Septimius Severus, the first of the dynasty, cultivated the army's support and substituted equestrian officers for senators in key administrative positions. His son, Caracalla, extended full Roman citizenship to all free inhabitants of the empire. Increasingly unstable and autocratic, Caracalla was assassinated by Macrinus, who succeeded him, before being assassinated and succeeded by Elagabalus. Alexander Severus, the last of the dynasty, was increasing unable to control the army, and was assassinated in 235. His death marked the end of the Pax Romana, or "Roman Peace".

Crisis of the Third Century and the later emperors (235–395)

The Crisis of the Third Century is a commonly applied name for the crumbling and near collapse of the Roman Empire between 235 and 284. During this time, 25 emperors reigned, and the empire experienced extreme military, political, and economic crises. This period ended with the accession of Diocletian, who reigned from 284 until 305, and who solved many of the acute problems experienced during this crisis. However, the core problems would remain and cause the eventual destruction of the western empire. Diocletian saw the vast empire as ungovernable, and therefore split the empire in half and created two equal emperors to rule under the title of Augustus. In doing so, he effectively created what would become the Western Roman Empire and the Eastern Roman Empire. In 293 authority was further divided, as each Augustus took a junior Emperor called a Caesar to provide a line of succession. This constituted what is now known as the Tetrarchy ("rule of four"). The transitions of this period mark the beginnings of Late Antiquity.

The Tetrarchy would effectively collapse with the death of Constantius Chlorus, the first of the Constantinian dynasty, in 306. Constantius's troops immediately proclaimed his son Constantine the Great as Augustus. A series of civil wars broke, which ended with the entire empire being united under Constantine, who legalised Christianity definitively in 313 through the Edict of Milan. In 361, after decades of further civil war, Julian became emperor. His edict of toleration in 362 ordered the reopening of pagan temples, and, more problematically for the Christian Church, the recalling of previously exiled Christian bishops. Julian eventually resumed the war against Shapur II of Persia, although he received a mortal wound in battle and died in 363. His officers then elected Jovian emperor. Jovian is remembered for ceding terrorities won from the Persians, dating back to Trajan, and for restoring the privileges of Christianity, before dying in 364.

Upon Jovian's death, Valentinian I, the first of the Valentinian dynasty, was elected Augustus, and chose his brother Valens to serve as his co-emperor. In 365, Procopius managed to bribe two legions, who then proclaimed him Augustus. War between the two rival Eastern Roman Emperors continued until Procopius was defeated, although in 367, eight-year-old Gratian was proclaimed emperor by the other two. In 375 Valentinian I led his army in a campaign against a Germanic tribe, but died shortly thereafter. Succession did not go as planned. Gratian was then a 16-year-old and arguably ready to act as Emperor, but the troops proclaimed his infant half-brother emperor under the title Valentinian II, and Gratian acquiesced.

Meanwhile, the Eastern Roman Empire faced its own problems with Germanic tribes. One tribe fled their former lands and sought refuge in the Eastern Roman Empire. Valens let them settle on the southern bank of the Danube in 376, but they soon revolted against their Roman hosts. Valens personally led a campaign against them in 378. However this campaign proved disastrous for the Romans. The two armies approached each other near Adrianople, but Valens was apparently overconfident of the numerical superiority of his own forces over the enemy. Valens, eager to have all of the glory for himself, rushed into battle, and on 9 August 378, the Battle of Adrianople resulted in a crushing defeat for the Romans, and the death of Valens. Contemporary historian Ammianus Marcellinus estimated that two thirds of the Roman army were lost in the battle. The battle had far-reaching consequences, as veteran soldiers and valuable administrators were among the heavy casualties, which left the Empire with the problem of finding suitable leadership. Gratian was now effectively responsible for the whole of the Empire. He sought however a replacement Augustus for the Eastern Roman Empire, and in 379 choose Theodosius I.

Theodosius, the founder of the Theodosian dynasty, proclaimed his five year old son Arcadius an Augustus in 383 in an attempt to secure succession. HispanicCelt general Magnus Maximus, stationed in Roman Britain, was proclaimed Augustus by his troops in 383 and rebelled against Gratian when he invaded Gaul. Gratian fled, but was assassinated. Following Gratian's death, Maximus had to deal with Valentinian II, at the time only twelve years old, as the senior Augustus. Maximus soon entered negotiations with Valentinian II and Theodosius, attempting to gain their official recognition, although Negotiations were unfruitful. Theodosius campaigned west in 388 and was victorious against Maximus, who was then captured and executed. In 392 Valentinian II was murdered, and shortly thereafter Arbogast arranged for the appointment of Eugenius as emperor. However, the eastern emperor Theodosius I refused to recognise Eugenius as emperor and invaded the West, defeating and killing Arbogast and Eugenius. He thus reunited the entire Roman Empire under his rule. Theodosius was the last Emperor who ruled over the whole Empire. As emperor, he made Christianity the official religion of the Roman Empire. After his death in 395, he gave the two halves of the Empire to his two sons Arcadius and Honorius. The Roman state would continue to have two different emperors with different seats of power throughout the 5th century, though the Eastern Romans considered themselves Roman in full. The two halves were nominally, culturally and historically, if not politically, the same state.

Decline of the Western Roman Empire (395–476)

After 395, the emperors in the Western Roman Empire were usually figureheads, while the actual rulers were military strongmen. The year 476 is generally accepted as the formal end of the Western Roman Empire. That year, Orestes refused the request of Germanic mercenaries in his service for lands in Italy. The dissatisfied mercenaries, led by Odoacer, revolted, and deposed the last western emperor, Romulus Augustus. This event has traditionally been considered the fall of the Western Roman Empire. Odoacer quickly conquered the remaining provinces of Italy, and then sent the Imperial Regalia back to the Eastern Roman Emperor Zeno. Zeno soon received two deputations. One was from Odoacer, requesting that his control of Italy be formally recognised by the Empire, in which case he would acknowledge Zeno's supremacy. The other deputation was from Nepos, the emperor before Romulus Augustus, asking for support to regain the throne. Zeno granted Odoacer's request. Upon Nepos's death in 480, Zeno claimed Dalmatia for the East. Odoacer attacked Dalmatia, and the ensuing war ended with Theodoric the Great, King of the Ostrogoths, conquering Italy.

The Empire became gradually less Romanised and increasingly Germanic in nature: although the Empire buckled under Visigothic assault, the overthrow of the last Emperor Romulus Augustus was carried out by federated Germanic troops from within the Roman army rather than by foreign troops. In this sense had Odoacer not renounced the title of Emperor and named himself "King of Italy" instead, the Empire might have continued in name. Its identity, however, was no longer Roman – it was increasingly populated and governed by Germanic peoples long before 476. The Roman people were by the fifth century "bereft of their military ethos and the Roman army itself a mere supplement to federated troops of Goths, Huns, Franks and others fighting on their behalf. Many theories have been advanced in explanation of the decline of the Roman Empire, and many dates given for its fall, from the onset of its decline in the third century to the fall of Constantinople in 1453. Militarily, however, the Empire finally fell after first being overrun by various non-Roman peoples and then having its heart in Italy seized by Germanic troops in a revolt. The historicity and exact dates are uncertain, and some historians do not consider that the Empire fell at this point. Disagreement persists since the decline of the Empire had been a long and gradual process rather than a single event.

Eastern Roman/Byzantine Empire (476–1453)

As the Western Roman Empire declined during the 5th century, the richer Eastern Roman Empire would be relieved of much destruction, and in the mid 6th century the Eastern Roman Empire (known also as the Byzantine Empire) under the emperor Justinian I reconquered Italy and parts of Illyria from the Ostrogoths, North Africa from the Vandals, and southern Hispania from the Visigoths. The reconquest of southern Hispania was somewhat ephemeral, but North Africa served the Byzantines for another century, Italy for another 5 centuries, and Illyria almost a millennium.

Of the many accepted dates for the end of the classical Roman state, the latest is 610. This is when the Emperor Heraclius made sweeping reforms, forever changing the face of the empire. Greek was readopted as the language of government and Latin influence waned. By 610, the Eastern Roman Empire had come under Greek influence and became what many modern historians now call the Byzantine Empire, although the Empire was never called thus by its inhabitants (rather it was called Romania, Basileia Romaion or Pragmata Romaion, meaning "Land of the Romans", "Kingdom of the Romans"), who still saw themselves as Romans, and their state as the rightful successor to the ancient empire of Rome. The sack of Constantinople at the hands of the Fourth Crusade in 1204 is sometimes used to date the end of Eastern Roman Empire: the destruction of Constantinople and most of its ancient treasures, total discontinuity of leadership, and the division of its lands into rival states with a Catholic-controlled "Emperor" in Constantinople itself was a blow from which the Empire never fully recovered. Nevertheless, the Byzantines continued to call themselves Romans until their fall to Ottoman Turks in 1453. That year the eastern part of the Roman Empire was ultimately ended by the Fall of Constantinople. Even though Mehmed II, the conqueror of Constantinople, declared himself the Emperor of the Roman Empire (Caesar of Rome / Kayser-i Rum) in 1453, Constantine XI is usually considered the last Roman Emperor. The Greek ethnic self-descriptive name Roman survives to this day.

Campaign History of the Roman Empire

Principate (27 BC–AD 235)

Between the reigns of the emperors Augustus and Trajan, the Roman Empire achieved great territorial gains in both the East and the West. In the West, following several defeats in 16 BC, Roman armies pushed north and east out of Gaul to subdue much of Germania. Despite the loss of a large army almost to the man in Varus' famous defeat in the Battle of the Teutoburg Forest in AD 9, Rome recovered and continued its expansion up to and beyond the borders of the known world. The Romans invaded Britain in 43 AD, forcing their way inland, and building two military bases to protect against rebellion and incursions from the north, from which Roman troops built and manned Hadrian's Wall. Emperor Claudius ordered the suspension of further attacks across the Rhine, setting what was to become the permanent limit of the Empire's expansion in this direction. Further east, Trajan turned his attention to Dacia. Following an uncertain number of battles, Trajan marched into Dacia, besieged the Dacian capital and razed it to the ground. With Dacia quelled, Trajan subsequently invaded the Parthian empire to the east, his conquests taking the Roman Empire to its greatest extent.

In 69 AD, Marcus Salvius Otho had the Emperor Galba murdered and claimed the throne for himself, but Vitellius had also claimed the throne. Otho left Rome, and met Vitellius at the First Battle of Bedriacum, after which the Othonian troops fled back to their camp, and the next day surrendered to the Vitellian forces. Meanwhile, the forces stationed in the Middle East provinces of Judaea and Syria had acclaimed Vespasian as emperor. Vespasians' and Vitellius' armies met in the Second Battle of Bedriacum, after which the Vitellian troops were driven back into their camp. Vespasian, having successfully ended the civil war, was declared emperor.

The first Jewish-Roman War, sometimes called The Great Revolt, was the first of three major rebellions by the Jews of Judaea Province against the Roman Empire. Earlier Jewish successes against Rome only attracted greater attention from Emperor Nero, who appointed general Vespasian to crush the rebellion. By the year 68, Jewish resistance in the North had been crushed. In 115, revolt broke out again in the province, leading to the second Jewish-Roman war known as the Kitos War, and again in 132 in what is known as Bar Kokhba's revolt. Both were brutally crushed.

Due in large part to their employment of powerful heavy cavalry and mobile horse-archers, the Parthian Empire was the most formidable enemy of the Roman Empire in the east. Trajan had campaigned against the Parthians and briefly captured their capital, putting a puppet ruler on the throne, but the territories were abandoned. A revitalised Parthian Empire renewed its assault in 161, and defeated two Roman armies. General Gaius Avidius Cassius was sent in 162 to counter the resurgent Parthia. The Parthian city of Seleucia on the Tigris was destroyed, and the Parthians made peace but were forced to cede western Mesopotamia to the Romans. In 197, Emperor Septimius Severus waged a brief and successful war against the Parthian Empire, during which time the Parthian capital was sacked, and the northern half of Mesopotamia was restored to Rome. Emperor Caracalla marched on Parthia in 217 from Edessa to begin a war against them, but he was assassinated while on the march. In 224, the Parthian Empire was crushed not by the Romans but by the rebellious Persian vassal king Ardashir, who revolted, leading to the establishment of Sassanid Empire of Persia, which replaced Parthia as Rome's major rival in the East.

Dominate (235–395)

Although the exact historicity is unclear, some mix of Germanic peoples, Celts, and tribes of mixed Celto-Germanic ethnicity were settled in the lands of Germania from the first century onwards. The essential problem of large tribal groups on the frontier remained much the same as the situation Rome faced in earlier centuries, the third century saw a marked increase in the overall threat. The assembled warbands of the Alamanni frequently crossed the boarder, attacking Germania Superior such that they were almost continually engaged in conflicts with the Roman Empire. However, their first major assault deep into Roman territory didn't come until 268. In that year the Romans were forced to denude much of their German frontier of troops in response to a massive invasion by another new Germanic tribal confederacy, the Goths, from the east. The pressure of tribal groups pushing into the Empire was the end result of a chain of migrations with its roots far to the east. The Alamanni seized the opportunity to launch a major invasion of Gaul and northern Italy. However, the Visigoths were defeated in battle that summer and then routed in the Battle of Naissus. The Goths remained a major threat to the Empire but directed their attacks away from Italy itself for several years after their defeat.

The Alamanni on the other hand resumed their drive towards Italy almost immediately. They defeated Aurelian at the Battle of Placentia in 271 but were beaten back for a short time, only to reemerge fifty years later. In 378 the Goths inflicted a crushing defeat on the Eastern Empire at the Battle of Adrianople. At the same time, Franks raided through the North Sea and the English Channel, Vandals pressed across the Rhine, Iuthungi against the Danube, Iazyges, Carpi and Taifali harassed Dacia, and Gepids joined the Goths and Heruli in attacks round the Black Sea. At the start of the fifth century AD, the pressure on Rome's western borders was growing intense.

A military that was often willing to support its commander over its emperor meant that commanders could establish sole control of the army they were responsible for and usurp the imperial throne. The so-called Crisis of the Third Century describes the turmoil of murder, usurpation and in-fighting that is traditionally seen as developing with the murder of the Emperor Alexander Severus in 235. Emperor Septimius Severus was forced to deal with two rivals for the throne: Pescennius Niger and then Clodius Albinus. Severus' successor Caracalla passed uninterrupted for a while until he was murdered by Macrinus, who proclaimed himsef emperor in his place. The troops of Elagabalus declared him to be emperor instead, and the two met in battle at the Battle of Antioch in 218 AD, in which Macrinus was defeated. However, Elagabalus was murdered shortly afterwards and Alexander Severus was proclaimed emperor who, after a short reign, was murdered in turn. His murderers raised in his place Maximinus Thrax. However, just as he had been raised by the army, Maximinus was also brought down by them and was murdered when it appeared to his forces as though he would not be able to best the senatorial candidate for the throne, Gordian III.

Gordian III's fate is not certain, although he may have been murdered by his own successor, Philip the Arab, who ruled for only a few years before the army again raised a general to proclaimed emperor, this time Decius, who defeated Philip in the Battle of Verona to seize the throne. Gallienus, emperor from 260 AD to 268 AD, saw a remarkable array of usurpers. Diocletian, a usurper himself, defeated Carinus to become emperor. Some small measure of stability again returned at this point, with the empire split into a Tetrarchy of two greater and two lesser emperors, a system that staved off civil wars for a short time until 312 AD. In that year, relations between the tetrarchy collapsed for good. From 314 AD onwards, Constantine the Great defeated Licinius in a series of battles. Constantine then turned to Maxentius, beating him in the Battle of Verona and the Battle of Milvian Bridge.

After overthrowing the Parthian confederacy, the Sassanid Empire that arose from its remains pursued a more aggressive expansionist policy than their predecessors and continued to make war against Rome. In 230, the first Sassanid emperor attacked Roman territory, and in 243, Emperor Gordian III's army defeated the Sassanids at the Battle of Resaena. In 253 the Sassanids under Shapur I penetrated deeply into Roman territory, defeating a Roman force at the Battle of Barbalissos and conquering and plundering Antiochia. In 260 at the Battle of Edessa the Sassanids defeated the Roman army and captured the Roman Emperor Valerian. There was a lasting peace between Rome and the Sassanid Empire between 297 and 337 following a treaty between Narseh and Emperor Diocletian. However, just before the death of Constantine I in 337, Shapur II broke the peace and began a twenty-six year conflict, attempting with little success to conquer Roman fortresses in the region. Emperor Julian met Shapur in 363 in the Battle of Ctesiphon outside the walls of the Persian capital. The Romans were victorious but were unable to take the city and were forced to retreat. There were several future wars, although all brief and small-scale.

Collapse of the Western Empire (395–476)

Rome's last gasp began when the Visigoths revolted around 395 AD. Led by Alaric I, in 402 AD they besieged Mediolanum, the capital of Roman Emperor Honorius. The arrival of the Roman Stilicho and his army forced Alaric to relieve the siege and move towards Hasta (modern Asti) in western Italy, where Stilicho attacked it at the Battle of Pollentia, capturing Alaric's camp. Stilicho again attacked at the Battle of Verona and again defeated Alaric, forcing him to withdraw from Italy. In 405 AD, the Ostrogoths invaded Italy itself, but were defeated. However, in 406 AD an unprecedented number of tribes took advantage of the freezing of the Rhine to cross en masse, encountering little resistance and completely over-running Gaul. Despite this grave danger, or perhaps because of it, the Roman army continued to be wracked by usurpation.

It is in this climate that, despite his earlier setback, Alaric returned again in 410 and managed to sack Rome. The Roman capital had by this time moved to the Italian city of Ravenna, but some historians view 410 as an alternative date for the true fall of the Roman Empire. Without possession of Rome or many of its former provinces, and increasingly Germanic in nature, the Roman Empire after 410 had little in common with the earlier Empire. By 410 AD, Britain had been mostly denuded of Roman troops, and by 425 AD was no longer part of the Empire, and much of western Europe was beset "by all kinds of calamities and disasters", coming under barbarian kingdoms ruled by Vandals, Suebians, Visigoths and Burgundians.

The remainder of Rome's territory, if not its nature, was defended for several decades following 410 largely by Flavius Aëtius, who managed to play off each of Rome's barbarian invaders against one another. In 436 he led a Hunnic army against the Visigoths at the Battle of Arles, and again in 436 at the Battle of Narbonne. In 451 he led a combined army, including his former enemy the Visigoths, against the Huns at the Battle of the Catalaunian Plains. Despite being the only clear champion of the Empire at this point Aëtius was slain by the Emperor Valentinian III's own hand, leading Sidonius Apollinaris to observe, "I am ignorant, sir, of your motives or provocations; I only know that you have acted like a man who has cut off his right hand with his left".

Carthage, the second largest city in the empire, was lost along with much of North Africa in 439 to the Vandals, and the fate of Rome seemed sealed. By 476, what remained of the Empire was completely in the hands of federated Germanic troops and when they revolted under Odoacer and deposed Emperor Romulus Augustus there was nobody to stop them. Odoacer happened to hold the part of the Empire around Italy and Rome but other parts of the Empire were ruled by Visigoths, Ostrogoths, Franks, Alans and others. The Empire in the West had fallen, and its remnant in Italy was no longer Roman in nature. The Byzantine Empire and the Goths continued to fight over Rome and the surrounding area for many years, though by this point Rome's importance was negligible. At this point in time, the Eastern Roman Empire stands alone, and events in Roman military history fall under the category of Byzantine military history. Following years of grinding war the city was by 540 AD near-abandoned and desolate with much of its environment turned into an unhealthy marsh, an inglorious end for a city that once ruled much of the known world.

Legacy

National Geographic aptly described the legacy of the Roman Empire in The World According to Rome:

Several states claimed to be the Roman Empire's successors after the fall of the Western Roman Empire. The Holy Roman Empire, an attempt to resurrect the Empire in the West, was established in 800 when Pope Leo III crowned Frankish King Charlemagne as Roman Emperor on Christmas Day, though the empire and the imperial office did not become formalised for some decades. After the fall of Constantinople, the Russian Tsardom, as inheritor of the Byzantine Empire's Orthodox Christian tradition, counted itself the third Rome (with Constantinople having been the second). And when the Ottomans, who based their state on the Byzantine model, took Constantinople in 1453, Mehmed II established his capital there and claimed to sit on the throne of the Roman Empire, and he even went so far as to launch an invasion of Italy with the purpose of "re-uniting the Empire", although Papal and Neapolitan armies stopped his march on Rome at Otranto in 1480. Constantinople was not officially renamed Istanbul until 28 March 1930.

Excluding these states claiming its heritage, if the traditional date for the founding of Rome is accepted as fact, the Roman state can be said to have lasted in some form from 753 BC to the fall in 1461 of the Empire of Trebizond (a successor state and fragment of the Byzantine Empire which escaped conquest by the Ottomans in 1453), for a total of 2,214 years. The Roman impact on Western and Eastern civilisations lives on. In time most of the Roman achievements were duplicated by later civilisations. For example, the technology for cement was rediscovered 1755–1759 by John Smeaton.

The Empire contributed many things to the world, such as a calendar with leap years, the institutions of Christianity and aspects of modern neo-classicistic and Byzantine architecture. The extensive system of roads that was constructed by the Roman Army lasts to this day. Because of this network of roads, the time necessary to travel between destinations in Europe did not decrease until the 19th century, when steam power was invented. Even modern Astrology comes to us directly from the Romans.

The Roman Empire also contributed its form of government, which influences various constitutions including those of most European countries and many former European colonies. In the United States, for example, the framers of the Constitution remarked, in creating the Presidency, that they wanted to inaugurate an "Augustan Age". The modern world also inherited legal thinking from Roman law, fully codified in Late Antiquity. Governing a vast territory, the Romans developed the science of public administration to an extent never before conceived or necessary, creating an extensive civil service and formalised methods of tax collection.

While in the West the term Roman acquired a new meaning in connection with the church and the Pope of Rome the Greek form Romaioi remained attached to the Greek-speaking Christian population of the Eastern Roman Empire (a name still used, at times, by modern Greeks in addition to their common appellation).

The Roman Empire's territorial legacy of controlling the Italian peninsula would serve as an influence to Italian nationalism and the unification (Risorgimento) of Italy in 1861.

References

Notes

Frank Frost Abbott (1901). A History and Description of Roman Political Institutions. Elibron Classics.

John Bagnell Bury, A History of the Roman Empire from its Foundation to the death of Marcus Aurelius, 1913

Winston Churchill, A History of the English-Speaking Peoples, Cassell, 1998, ISBN 0-304-34912-7